Electric circuit breaker



Feb. 27, 1934. w 5 PAUL I 1,949,258

ELECTRIC CIRCUIT BREAKER Filed May 20, 1932 01! Level.

Ihvehtor:

William E. Paul,

Hi 5 AttoThey.

Patented Feb. 27, 1934 UNITED STATES PATENT OFFICE ELECTRIC CIRCUITBREAKER New York Application May 20, 1932. Serial No. 612,523

Claims.

My invention relates to electric circuit breakers, more particularly tomultiple-break circuit lnterrupters of the oil blast explosion chamberype.

5 The principal object of my invention is the provision of an improvedcircuit breaker of the aforesaid type which shall be efficient andpositive in operation and capable of interrupting large amounts of powerat high voltages.

My invention will be more fully set forth in the following descriptionreferring to the accompanying drawing, and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming a part of this specification.

Referring to the drawing, Fig. 1 is a fragmentary view in perspective,partly in section, of a single pole of a circuit breaker embodying thepresent invention, Fig. 2 is a sectional plan view taken along the line2-2 of Fig. 1, and Fig. 3 is a sectional plan view taken along the line3-3 of Fig. 1.

The circuit breaker illustrated comprises an explosion chamber pot .1housing the relatively fixed contact structure, and contact actuatingmeans as a conducting bridging member 2 operated in any suitable mannerby the lift rod 3. Although the breaker described is of the double poletype wherein the bridging member 2 interconnects two similar explosionpots, illustration and description of the structure and operation of asingle pole will be sufficient in understanding the invention. Theexplosion chamber pots and bridging member are immersed in a well 35known manner in insulating liquid. as oil, for

the purpose of properly insulat'ing the conducting parts and forefiecting interruption of arcing by individual blasts of the insulatingliquid in a manner presently described.

10 The explosion chamber pot 1 may be constructed in any suitable mannerso as to be mechanically strong and insulated properly for the operatingvoltage. In the present instance a lead-in bushing 4 for the conductorstud 5 has mounted at the lower end thereof a cup-shaped conductingmember 6. Suitably secured to the member 6 is an insulating cylindricalstructure 7 formed in two sections for the purpose of assembly andspaced from the upper wall of the member 6 to form a pressure generatingchamber 8. The aforesaid sections may be secured together, as bythrough-bolts '7 which extend longitudinally of the sections fromcountersunk openings.

The pressure chamber 8 is in communication through a vertical passage 9with a plurality of radially disposed exhaust passages 10 leading fromthe central passage 9 to the body of insulating liquid exteriorly of theexplosion pot as best shown in Fig. 2. In high voltage operation 59 aninsulating shield 11 is commonly used and this shield, which iscylindrical in form, may be suitably supported at its lower edge by theexplosion pot as indicated at 12.

The contact structure comprises a plurality of coacting contacts allconnected in series and arranged so that opening of one pair of contactscauses an individual blast of insulating liquid across the arc formedat' each of the other pairs of contacts. To this end a pair of contacts13 7 and 14 are separable in the pressure chamber 8, contact 13 beingfixed and forming part of the conducting member 6 and contact 14comprising a rod guided for vertical movement in the insulatingstructure 7 and resiliently biased, as by a spring 15, towards opencircuit position. A plurality of other pairs of coacting contacts arearranged to separate transversely of the passages 10, said contactscomprising coacting pairs 1617, 18--19, and 2021. The contact 16, whichis a 1 part of the rod comprising contact 14, is biased by spring 15into engagement with the contact 1'7, and the contacts 19 and 20 arebiased by springs 22 and 23, respectively, into engagement with contacts18 and 21 when the switch is in 1 closed position.

The pairs of contacts above described are suitably connected in series,the circuit being completed from the lead-in conductor 5 to the bridgingmember 2 through the conducting member 6, contacts 13-44, 161'7,conducting strip 24, contacts 1819, conducting strip 25, (Fig. 3)contacts 202l, and conducting strip 26. The movable contacts 17, 18, and21 are suitably mounted at the end of the bridging member 2, as on theinsulating blocks 27.

When the switch is in closed circuit position the bridging member 2 ispositioned so that the movable contacts 1'7. 18, and 21 are within andextend through the corresponding alined aper- 10o tures 10'communicating with passages 10 and the above described contacts engagewithin the radially disposed passages. The contact 17 in closinglikewise biases the contact 14 upwardly into engagement with itscoacting contact 13 m5 so that the circuit is complete through all thecontacts. The conducting strip 25 is connected to and moves with thecontacts 19 and 20 within an arcuate slot 25 formed in the insulatingstructure 7, as illustrated in Figs. 1 and 3. n

a When the circuit is to be opened as by lowering the bridging member 2,the initial opening causes immediate separation of the contacts 13, 14in the pressure chamber. The remaining cons tacts,v however, are stillin engagement due to the following action of the biasing springs. Aftera short travel the contacts 16, 19, and are checked by the stop collar16 and the conducting strip 25, respectively, so that simultaneousoperation of the contacts occurs transversely of the passages 10. I

"During the initial opening movement the pressure generated by the arcbetween contacts 13 and 14 in the pressure chamber drives insulatingliquid at high velocity downwardly through the passage 9 and outwardlythrough the radial pasages 10 transversely of the arcs formed therein.

The interrupting action of simultaneous blasts of insulating liquid onindividual arcs in series is effective at high voltages. The movable contacts 17, 18, and 21move through the apertures 10' to open circuitposition within the main body of insulating liquid so that thecontactsare insulated and separated a suitable distance. After a circuit openingoperation the insulating liquid refills the explosion pot, a vent 8' inthe upper part of chamber 8 insuring refilling by preventing theformation of a gas pocket.

The radial arrangement of the oil blast passages enables the normalmagnetic forces of the circuit to be interrupted to'assist the action ofthe blast. It-is well known that the magnetic forces of a loop tend toexpand the loop so that in a;circuit breaker of the type in questionthemagnetic forces tend to blow thearc outwardly and away from the loop;,The arcs in the radial arrangement thereof herein illustrated, and thatchanges and modifications may occur to one skilled in the art withoutdeparting from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the nitedStates is: 1. A circuit br l comprising an explosion chamber p'ot immerin an insulating liquid, means forming in said pot a pressure generatingchamber and a plurality of passages including a centrally disposedpassage communicating with said chamber and with the exterior of saidpot, respectively,'a pair of coacting contacts separable in saidpressure generating chamber. a plurality of pairs of arc interruptingcontacts separable transversely of said es, and an actuating J membercommon to the aforesaid pairs of contacts arranged to lower the movableare interrupting contacts intovssid insulating liquid. the

' aforesaid contacts connected'in series so that areing pressuregenerated in said'chamber is effective to produce-an individual blast ofinsulating liquid from said central e across the arc in each of said esupon-opening d the circuit.

2. A circuit breaker comprising an explosion chamber pot forming apressure generating chamber and apluralityof radially disposed exhaustpassages communicating with said chamber. an insulating liquid in whichsaid explosion pot is immersed, a pair of coasting contacts separable jwithin said pressure chamber, and a plurality of pairs of coactingcontacts, each pair disposed transversely of one of said passages, saidcontacts connected in series arranged so that arcing pressure generated\within said chamber is effective to cause a blast of insulating liquidthrough each of said passages and across the contacts therein uponopening of the circuit.

3. A circuit breaker of the oil blast type com.- prising an explosionchamber pot forming an upper pressure generating chamber and a pluralityof radially disposed exhaust passages beneath and communicatingwith'sa'ld chamber, an insulating liquid in which said explosion pot isimmersed, a pair of coacting contacts separable within said pressurechamber, a plurality ofv pairs of coasting contacts, each pair separablem in one of said pa es and including a contact movable transverselyofsaid e. and actuating means arranged to lower said movable contactsinto said insulating liquid. 4. A circuit breaker comprising anexplosion 05 Chamber pot forming a pressure generating chamber and aplurality of radially ex-" haust passages, said passages having a commoncentral passage communicating with said chamher, a pair of contactsseparable in said pressure no chamber, aplurality of pairs of contacts,eadi separable inand transversely of one of said rsdial passages, abridging member carrying the movable contacts of said lastrnamed pairsof contacts, and springs mounted in said pot blue 5 ing the contactscoacting with said movable contacts into limited following engagementwith said movable contacts,one of said movable contacts controllingengagement and disengagement of said first-named pair of contacts.

5. A circuit breaker of the oil blast type corni prising a conductingbridging member for cgnnecting a pair contact structures, each structurecomprising an' explosion chamber pot forming a pressure generatingchamber and a plu- "5 rality of exhaust passages leading therefrom. an Iinsulating liquid in which said structure is immersed, a plurality ofpairs of contacts ed in series including contacts separable in saidpressure chamber and contacts separablein each of'said passages arrangedso that pressure generated in said chamber on opening of the circuitcauses individual blasts of insulating liquid through said passages andthe arcs formed theresaid passages being arranged with respect to themagnetic forces ofv the circuit to be interrupted so that the normalmagnetic blowout ef-. feet is in the direction of said blasts.

wnrrm a. nun

